<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>设置元素的高度和宽度</title>
</head>

<body>


    <style>
        div {
            height: 200px;
            width: 50%;
            background-color: powderblue;
        }
    </style>

    <h1>设置元素的高度和宽度</h1>

    <p>这个 div 元素的高度为 200 像素，宽度为 50%：</p>

    <div></div>
</body>

</html>